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  Eight-speed powertrain of automatic transmission for vehicleUSPTO Application #: 20080108472Title: Eight-speed powertrain of automatic transmission for vehicle Abstract: A eight-speed powertrain of an automatic transmission for a vehicle combining four simple planetary gear set with a plurality of clutches and brakes to realize seventh forward speed or eighth forward speed and two reverse speeds can improve power delivery performance and reduce fuel consumption. (end of abstract) Agent: Morgan, Lewis & Bockius LLP (sf) - Palo Alto, CA, US Inventor: Kang Soo Seo USPTO Applicaton #: 20080108472 - Class: 475275 (USPTO) The Patent Description & Claims data below is from USPTO Patent Application 20080108472. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS-REFERENCE TO RELATED APPLICATION [0001]This application claims priority to and the benefit of Korean Patent Application No. 10-2006-0109091 filed in the Korean Intellectual Property Office on Nov. 6, 2006, the entire contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION [0002](a) Field of the Invention [0003]The present invention relates to an automatic transmission, and more particularly, to a powertrain of an automatic transmission. [0004](b) Description of the Related Art [0005]A multi-stage gearshift mechanism of an automatic transmission includes a plurality of planetary gear sets. A powertrain having such a plurality of planetary gear sets varies the torque in multi-stages and outputs it to an output shaft when receiving a converted engine torque from a torque converter. The more speeds the powertrain of an automatic transmission has, the better the power performance and fuel consumption. Therefore, it is desirable for powertrains to have as many speeds as possible. Even for the same number of speeds, durability, power transmission efficiency, and size/weight of a transmission are substantially dependent on how planetary gear sets are arranged. Therefore, research for more structural strength, less power loss, and more compact packaging are continuously being conducted. [0006]For a manual transmission, too many speeds cause a driver the inconvenience of excessive manual shifting. However, for an automatic transmission, a transmission control unit automatically executes shifting by controlling the operation of the power train, and therefore, more speeds usually implies more merits. [0007]Accordingly, research of four-speed and five-speed powertrains has been undertaken, and recently, a powertrain of an automatic transmission enabling six forward speeds and one reverse speed has been developed. On the other hand, a development for the automatic transmission which can realize more speed implies more merits. [0008]The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. SUMMARY OF THE INVENTION [0009]Embodiments of the present invention provide an eight-speed powertrain of an automatic transmission having advantages of improving power delivery performance and reducing fuel consumption by combining four planetary gear sets and a plurality of clutches and brakes. [0010]In an exemplary embodiment of the present invention, an eight-speed powertrain of an automatic transmission for a vehicle includes a first shift portion comprising a first and a second planetary gear sets which is a simple planetary gear set, an input path to which power directly is input from an input shaft, and an intermediate output path outputting the power by decelerating and a second shift portion comprising a third and a fourth planetary gear set which is the simple planetary gear set, a first intermediate input path receiving the power through the intermediate output path of the first shift portion, a second intermediate input path which the power is variably input from the input shaft, and a final output path shifting and outputting the power input through the first and the second intermediate input path, wherein a plurality of frictional elements operational elements forming the first and the second shift portion disposed between the operational elements and between the operational elements and a transmission housing such that the operational elements operates selectively as an input element and a fixed element. [0011]The first planetary gear set includes a single pinion planetary gear set including a first sun gear, a first ring gear, and a first planet carrier, the second planetary gear set includes a single pinion planetary gear set including a second sun gear, a second ring gear, and a second planet carrier, the third planetary gear set includes a single pinion planetary gear set including a third sun gear, a third ring gear, and a third planet carrier, and the fourth planetary gear set includes a single pinion planetary gear set including a fourth sun gear, a fourth ring gear, and a fourth planet carrier. [0012]The first shift portion comprises four operational elements by which the first ring gear and the second planet carrier are directly connect and the sun gear of the first planetary gear set and the sun gear of the second planetary gear set are directly connect. [0013]The four operational elements, the first operational element comprising the first sun gear and the second sun gear, the second operational element including the first planet carrier, the third operational element including the first ring gear and the second planet carrier, and the fourth operational element including the second ring gear. [0014]The fourth operational element includes the input path by being fixedly connected to the input shaft, the third operational element includes an intermediate output path, and the first and the second operational elements operates selectively as a fixed element. [0015]The second shift portion comprises four operational elements by which the third ring gear and the fourth planet carrier are directly connect, and the third sun gear and the fourth sun gear are variably connected. [0016]The four operational element, a fifth operational element comprises the fourth ring gear, a sixth operational element comprises the third ring gear and the fourth planet carrier, a seventh operational element comprises the third planet carrier, and a eighth operational element comprises the third sun gear and the fourth sun gear. [0017]The fifth operational element includes the first intermediate input path directly connected to the intermediate output path of the first shift portion, the sixth operational element includes the second intermediate input path variably connected to the input shaft, and the seventh operational element includes the final output path. [0018]The sixth operational element is operated as a fixed element by being variably connected to the transmission housing. [0019]The third sun gear and the fourth sun gear of the eighth operational element, are variably connected each together, and are variably connected to the transmission housing such that all of the third sun gear and the fourth sun gear or one thereof operate as fixed element. [0020]The third sun gear is variably connected to the transmission housing. [0021]The fifth operational element is variably connected to the transmission housing to operate as a fixed element. Continue reading... Full patent description for Eight-speed powertrain of automatic transmission for vehicle Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Eight-speed powertrain of automatic transmission for vehicle patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Eight-speed powertrain of automatic transmission for vehicle or other areas of interest. ### Previous Patent Application: Lubrication ports for a differential housing Next Patent Application: Power train of automatic transmission Industry Class: Planetary gear transmission systems or components ### FreshPatents.com Support Thank you for viewing the Eight-speed powertrain of automatic transmission for vehicle patent info. IP-related news and info Results in 1.31333 seconds Other interesting Feshpatents.com categories: Software: Finance , AI , Databases , Development , Document , Navigation , Error |
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